HAMPTONS real estate might finally be looking up. A 14-acre Southampton spread with a 1915 mansion belonging to the late Howard Gittis, the charismatic consigliere to billionaire Ronald Perelman, is in contract for about $45 million, reports The Post’s Jennifer Gould Keil. That’s down from its $59 million asking price two years ago and its most recent $49.5 million asking price. But it’s still way more that the $9 million Gittis paid for the property in the Estates section in 1993. The buyer is an unidentified, recession-proof financier.